1. Field of the Invention
This invention pertains to the construction industry. More particularly, it pertains to dry wall operations and to an apparatus for rapidly refilling dry wall cement dispensing tools.
2. Description of the Prior Art
Most everyone is familiar with dry wall construction. Dry wall comes in a sheet, generally four feet by eight feet in size and of a thickness ranging from one-half to seven-eights inches, having a sandwich construction with a gypsum center and heavy paper outer flat surfaces, cut to fit and placed against 2.times.4 wood or metal framing to form interior wall surfaces of most homes and offices. The sheets are butted together along their vertical and horizontal edges and nailed to the underlying frame. A two-inch wide elongated depression is formed along the peripheral edges to receive the nails that attach the sheets to the frame. It is mainly in this depression that dry wall cement and paper are later added to hide the nail heads and to which this invention is directed.
A dry wall finisher uses different tools to fill the depressions with one or more smooth thin layers of a water-base dry wall cement. Over the last or top layer is placed a thin paper tape so that the entire wall takes on a smooth, ripple-free surface that may be painted or overlaid with wall paper or other trimming. These tools are many and of varied sizes and shapes. Two of the most common are the nail spotter and the automatic taper.
The nail spotter comprises a magazine, called a "box-assembly" into which an inventory of dry wall cement is placed. A pair of spaced-apart wheels are located at the rear of the box and a flat blade is fixed at the front of the box next to a cement feed hole so that the box is supported for moving over the vertical dry wall surface. A handle extends from the box with which to manipulate the tool. A moveable cover is pivotally mounted over the open top of the box assembly and mechanically linked to apply pressure to the magazine full of cement to force a small amount to exude from the feed hole onto the wall. The nail spotter is used to fill hammer-made depressions and other dents formed in the dry wall during cutting, fitting and nailing it to the frame. The blade scrapes the cement over the depression to create the smooth finished surface.
The automatic taper is a more complex tool. It generally comprises an elongated hollow tube filled with an inventory of cement. At the front end of the tube is mounted a cross-axle for holding a roll of paper tape. Means are connected to the front end to unroll the tape in a controlled manner. A piston is slidably mounted inside the tube and presses against the inventory of dry wall cement from the rear end of the tube, forcing the cement toward the front and the tape. A cement issue aperture is set near the tape along with a blade or blades. The tool is pushed or pulled along the elongated depressions located about the peripheral edges of the dry wall to lay down a smooth thin layer of cement in the abutted depressions and overlay the cement with the finish dry wall paper to form a smooth, wrinkle-free surface.
There are dry wall finishing tools other than the two discussed herein, however, they all have one common trait, namely they hold an inventory of dry wall cement and this inventory becomes depleted during the dry wall finishing operation. Accordingly, these tools must be refilled with cement throughout the work day.
Dry wall cement is usually sold in five gallon buckets. The cement is wet and heavy, having the consistency of mortar but with a substantially finer particle size. Traditionally, the device used to reload a dry wall finishing tool is a hand-operated cement pump called a "stirrup pump" that is partially submerged in the open bucket of cement and supported therein by an elongated member attached to the top thereof that passes downward along the outside of the bucket, spaced-apart from the pump, to terminate in a flange upon which the operator places his foot when using the pump. A top-mounted pump handle is then manually moved up and down in a series of short strokes to slowly pump the cement from the bucket into the tool. In the case of the nail spotter, the box assembly is temporarily mated to the pump and the cement loaded in through the issue slot against the spring pressure to fill the magazine with an exudate of cement. In the case of the automatic taper, the issue hole is temporarily mated to the pump by a gooseneck that is attached to the pump, and the cement forced in through the issue aperture against the spring pressure. The pump handle is manipulated to slowly pump the cement into the tube.
While these dry wall finishing tools make for smooth finishing of installed dry wall, the overall process is time-consuming and very strenuous. The tools can be manipulated quite rapidly and the cement and paper quickly applied. However, the process of reloading the tools using the hand-operated stirrup pump is extremely slow and the pumping requirement is exhausting. Usually, the dry wall finisher becomes so worn out from pumping during the refill operation that the quickness and agility of using the tools are lost in the drudgery of the refill operation and the entire finishing process remains a slow, time-consuming operation with its attendant high labor costs.